I have two Profi 403 and one Profi 301 radios and I have never had a range issue. I use Novak Xxtra, Novak Mercury, Novak XXL and Airtronics FM receivers with the matching Airtronics receiver crystal for my transmitter crystal.

If a synthesized Tx module is developed for these Profi transmitters I would be extremely interested. Heck, I'd even volunteer to test one out for you guys at Hitec. Call me!